<?php

class TwitterHelper extends AppHelper {

	function aktt_make_clickable($tweet) {
		$tweet .= ' ';
		$tweet = preg_replace_callback('/@([a-zA-Z0-9_]{1,15})([) ])/', create_function('$matches', 'return $this->aktt_profile_link($matches[1], \'@\', $matches[2]);'), $tweet);
		$tweet = preg_replace_callback('/\#([a-zA-Z0-9_]{1,15}) /', create_function('$matches', 'return $this->aktt_hashtag_link($matches[1], \'#\', \' \');'), $tweet);
		$tweet = $this->make_clickable($tweet);
		return $tweet;
	}

	function aktt_profile_link($username, $prefix = '', $suffix = '') {
		return $prefix.'<a href="'.'http://twitter.com/'.$username.'">'.$username.'</a>'.$suffix;
	}

	function aktt_hashtag_link($hashtag, $prefix = '', $suffix = '') {
		return $prefix.'<a href="'.'http://search.twitter.com/search?q='.urlencode('#'.$hashtag).'">'.htmlspecialchars($hashtag).'</a>'.$suffix;
	}

	function make_clickable($ret) {
		$ret = ' ' . $ret;
		// in testing, using arrays here was found to be faster
		$ret = preg_replace_callback('#([\s>])([\w]+?://[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is', '$this->_make_url_clickable_cb', $ret);
		$ret = preg_replace_callback('#([\s>])((www|ftp)\.[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is', '$this->_make_web_ftp_clickable_cb', $ret);
		$ret = preg_replace_callback('#([\s>])([.0-9a-z_+-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,})#i', '$this->_make_email_clickable_cb', $ret);
		// this one is not in an array because we need it to run last, for cleanup of accidental links within links
		$ret = preg_replace("#(<a( [^>]+?>|>))<a [^>]+?>([^>]+?)</a></a>#i", "$1$3</a>", $ret);
		$ret = trim($ret);
		return $ret;
	}

	function _make_url_clickable_cb($matches) {
		$ret = '';
		$url = $matches[2];
		$url = clean_url($url);
		if ( empty($url) )
			return $matches[0];
		// removed trailing [.,;:] from URL
		if ( in_array(substr($url, -1), array('.', ',', ';', ':')) === true ) {
			$ret = substr($url, -1);
			$url = substr($url, 0, strlen($url)-1);
		}
		return $matches[1] . "<a href=\"$url\" rel=\"nofollow\">$url</a>" . $ret;
	}

	function _make_web_ftp_clickable_cb($matches) {
		$ret = '';
		$dest = $matches[2];
		$dest = 'http://' . $dest;
		$dest = clean_url($dest);
		if ( empty($dest) )
			return $matches[0];
		// removed trailing [,;:] from URL
		if ( in_array(substr($dest, -1), array('.', ',', ';', ':')) === true ) {
			$ret = substr($dest, -1);
			$dest = substr($dest, 0, strlen($dest)-1);
		}
		return $matches[1] . "<a href=\"$dest\" rel=\"nofollow\">$dest</a>" . $ret;
	}

	function _make_email_clickable_cb($matches) {
		$email = $matches[2] . '@' . $matches[3];
		return $matches[1] . "<a href=\"mailto:$email\">$email</a>";
	}

}
?>